Gearing



Aug. 21, 1956 w. H. mm 2,759,368

GEARING Filed Nov. 27, 1950 3 Sheets-Sheet l IN VEN TOR W. H. KlTTOGEARING Aug. 21, 1956 3 Sheets-Sheet 2 Filed NOV. 27, 1950 WWW g QM W lmhm 7 QM mE QM WMM United States Patent 0 GEARING William H. Kitto,Evanston, Ill., assignor to G-M Laboratories, Inc., Chicago, 11]., acorporation of Illinois Application November 27, 1950, Serial No.197,721

6 Claims. (Cl. 74-446) This invention relates to gearing which isparticularly adaptable for use in an improved floor polishing andscrubbing machine having a single rotary flat brush which normallysupports the weight of the machine.

The principal object of this invention is to provide an improved gearingconstruction for driving the rotary brush from the machine motor,wherein the gearing has long life under normal operating conditions,wherein gear noise is substantially eliminated, wherein porous bearingsand plastic gears are utilized to eliminate the necessity for gearboxes, gaskets, seals and the like, and wherein the gearing may beaccurately and inexpensively fabricated.

The improved floor polishing and scrubbing machine utilizing the gearingof this invention is fully illustrated and described in a co-pendingapplication Serial #197,725, filed on November 27, 1950, by Archie J.McMaster, William H. Kitto, and Kurt Burian. The machine includes a basemember which is preferably of an inverted cup shaped configuration. Asubstantially constant speed single phase induction motor is mounted onthe upper side of the base member with the motor shaft extendingdownwardly through the base member. A phasing reactor is also mounted onthe upper side of the base member. A cover is secured to the upper sideof the base member and encloses the motor and phasing reactor. The lowerend of the motor shaft operates a motor pinion meshing with a novelcluster gear carried by a bracket secured to the lower side of the basemember. The cluster gear also meshes with a novel output gear carried bya bracket also secured to the lower side of the base member. Mountingmeans detachably secure a flat rotary brush to the output gear to bedriven thereby. A centrifugal clutch is located between the motor shaftand the motor pinion.

All of the component parts of the machine are carried by the single basemember so that they may all be accurately positioned with respect toeach other with a minimum of efiort, thereby greatly reducingmanufacturing and assembly costs. Further, when the brush and cover areremoved, the various parts are exposed for ready inspection, cleaningand repair, if necessary.

In assembling the gearing, the cluster gear is brought into propermeshing relation with the motor pinion and then its supporting bracketis securely fastened in place on the base member. Then the output gearis brought into proper meshing relation with the cluster gear and itssupporting bracket is tightly secured to the base member. In this waycorrect meshing of the gearing is assured and the maintenance of closetolerances in the parts is not required. This further decreases thecosts of manufacture of the machine.

The engaging teeth of the motor pinion and cluster gear are helicallyformed to provide a downward thrust on the motor shaft and an upwardthrust on the cluster gear during operation for the purpose ofeliminating intermittent thrust motion of the motor shaft and clustergear and noise which would result therefrom. Suitable thrust bearingsare provided for the motor pinion and "ice cluster gear. The engagingteeth of the cluster gear and output gear are regularly formed and sincethe output gear, which carries the brush, supports the weight of themachine, it is also provided with a thrust bearing.

The gears are all rotatably journaled by means of porous bearingssupplied with suitable lubricant and the gears are formed of suitableplastic, such as nylon, for oilless and noiseless operation. As a resultthe necessity for gear boxes, seals, gaskets and the like is eliminated.The gears are unique in construction in that they include metal bodyportions, plastic tires having the gear teeth formed therein and novelmeans for securing the plastic tires to the body portions. The tires inblank form are secured to the body portions and then the gear teeth arehobbed in the plastic tires. This provides fast cutting of accurate gearteeth and eliminates the necessity of maintaining close tolerances inthe parts.

The output gear is provided with an annular boss and with pins havingconical heads for securing the brush to the output gear. The brush isdrawn against the annular boss of the output gear and since the brushforms the sole support for the machine, the drawing of the brush againstthe annular boss of the output gear squares up the machine and preventswobbling of the machine.

Further objects of this invention reside in the details of constructionof the gearing, the cooperative relationship between the component partsthereof and the features of the gearing which particularly adopt thegearing for use in the improved floor polishing and scrubbing machine.

Other objects and advantages of this invention will become apparent tothose skilled in the art upon reference to the accompanyingspecification, claims and drawings, in which:

Fig. 1 is a bottom plan view of a floor polishing or scrubbing machinewith the brush removed and utilizing the novel gearing of thisinvention;

Fig. 2 is an enlarged vertical sectional view taken through line 2-2 inFig. 1 and showing the brush assembled;

Fig. 3 is an enlarged sectional view of the cluster gear:

Fig. 4 is a sectional view taken along the line 4-4 of Fig. 3;

Fig. 5 is an exploded perspective view of the cluster gear;

Fig. 6 is a vertical sectional view through the output gear;

Fig. 7 is an exploded perspective view of the parts forming the outputgear; and

Fig. 8 is a partial bottom view of the output gear.

Referring first to Figs. 1 and 2, the floor polishing and scrubbingmachine utilizing the gearing of this invention is generally designatedat 10 and includes an inverted cup-shaped base member formed from sheetsteel having a side wall 11 and a top wall 12. The top wall 12 isrecessed at 13 and is formed with a central bearing seat 14 having aspherical bearing supporting surface 15.

Mounted on the upper side of the base member is an electric motor, whichmotor may be of the type described in the above mentioned co-pendingapplication Serial #197,725. The lower end of the motor shaft 22 carrieswithin the base member 11, a centrifugal clutch and motor pinionassembly, which is fully shown and described in said co-pendingapplication.

The motor pinion 153 meshes with a large diameter gear 192 of a clustergear also having a gear of smaller diameter 193. This cluster gear isrotatably carried on a shaft 194 which in turn is secured to a clustergear bracket 195, the bracket being adjustably secured to the lower sideof the upper wall 12 ,of the base member.

The cluster gear is illustrated in more detail in Figs.

3 to 5 and includes a body portion 197 which may be formed of die castzinc. The upper surface of the body portion 197 is provided with anannular boss 198 and also with a plurality of circumferentially spacedcircular bosses 199. 'The gear 192 is formed on a tire made of suitableplastic material such as nylon, the tire being provided with a centralopening 200 and a plurality of holes 201. The tire is placed on theupper surface of the body portion 197 with the central opening 200engaging the annular boss 198 and with the holes 201 receiving thebosses 199. In this way a driving relationship is established betweenthe tire and the body portion. A plate 203 having a central opening andholes 304 is provided for clamping the tire in place on the bodyportion. In this respect rivets 205 extend through the holes 204 andthrough hole-s in the bosses 199. The inner part of the-plate 203 restson an annular shoulder 292 formed on the upper side of the body portion197.

The body portion 197 has an extension or shank of reduced diameter uponwhich is mounted the gear 193, the gear being made of suitable plasticsuch as nylon. The body portion 197 is provided with a plurality ofprojections 297 extending between the gear teeth on the gear 193. Theseprojections 207 provide a driving connection between the body portion'197 and the gear 193. The gear 193 is provided with an internal recess208 for receiving a washer 209 which in turn is held in place by peeningover at 210 the lower extremity of the body portion 197. In this way thegear 193 is locked in place on the body portion 197.

A sintered porous bronze bearing 213 is secured within the body portion197 and it seats against an internal shoulder 212. An absorbent washer214 rests against the upper surface of the porous bearing 213 and theabsorbent washer is held in place by a metal washer 215, the metalwasher in turn being staked in place as illustrated at 216. Theabsorbent washer is impregnated with a suitable lubricant for supplyinglubricant to the porous bearing 213 for lubricating the running fitbetween the porous bearing and the cluster gear shaft 194. The washer215 in addition to encasing the absorbent washer 214 also acts as athrust washer for the cluster gear.

In forming the cluster gear the smaller diameter plastic gear 193 hasits teeth molded or otherwise formed thereon before the gear is appliedto the body portion. However, in the case of the larger diameter gear192, the plastic tire in blank form is first secured to the body portionand then the gear teeth are suitably hobbed or cut after assembly abouta center corresponding to the axis of the porous bearing. This assuresan accurate relation between the central axis of the cluster gear andthe teeth of the larger gear 192. The gear teeth may thus be accuratelyand rapidly formed with small expense in this manner.

The cluster gear is rotatably mounted on the shaft 194 which in turn isprovided at its upper end with a shoulder engaging the bracket 195, theshaft being held in place on the bracket 195 by peening over the upperend thereof as at 218. A resilient thrust washer 220 preferably made ofimpregnated cork is located between the bracket 195 and the washer 215.There is thus provided a resilient thrust bearing for the cluster gear.The bracket 195 is adjustably secured to the base member by screws 219.v

Preferably the gear teeth of the motor pinion 153 and the gear teeth ofthe gear 192 of the cluster gear are helically formed for the purpose ofmaintaining substantially constant thrust on the motor shaft and on thecluster gear. The direction of the helices is such that upon operationof the machine a downward thrust is provided on the motor shaft and anupward thrust on the cluster gear. This upward thrust is absorbed by theresilient upper thrust bearing of the cluster gear.

The smaller gear 193 of the cluster gear meshes with an output gear 225which is rotatably mounted on a'shaft 226, the shaft being carried by abracket 227 adjustably secured to the lower side of the upper wall 12 ofthe base member.

The output gear 225 is illustrated in more detail in Figs. 6 to 8. Theoutput gear includes a tire formed of suitable plastic material such asnylon in which the gear teeth are formed. It also includes a bodyportion 229 for carrying the tire. The body portion 229 may be formed ofdie cast zinc and is provided with an external shoulder 230 received ina groove formed in the lower side of the tire. The tire is provided withan internal surface 232 engaging the exterior of the body portion 229and the body portion is provided with a plurality of lugs 231 receivedin notches 233 in the tire. In this way a driving connection is providedbetween the tire and the body portion. The top of the body portion 229is provided with a plurality of circular bosses 234 which are receivedin holes 235 in a clamping disc 236. The outer edge of the clamping disc236 is provided with a downwardly extending flange 237 received in asuitable groove in the tire. The disc 236 is fastened to the bodyportion 229 by peening over the bosses 234 as indicated at 238 and alsosecurely clamps the tire in place on the body portion. The upper surfaceof the body portion is provided with an annular groove 240 in which isreceived an absorbent washer 241 impregnated with suitable lubricant.The disc 236 partially overlies the absorbent washer for retaining thesame in the annular groove. A sintered porous bronze bearing 242 iscarried by the body portion 229 and it is provided with an annularflange 243 which also partially overlies the absorbent washer 241. Theabsorbent washer 241 supplies lubricant to the porous bearing 242 forlubricating the running fit between the bearing and the shaft 226. Theflange 243 on 'the upper end of the bearing 242 also serves as a thrustsurface for the output gear and the thrust surface must be normal to theaxis of rotation of the output gear. To obtain the desired accuracy ashouldered punch is pressed into the bore of the bearing 213 with aninterference fit until the shoulder strikes the fiange for sizing thebore and squaring the flange. Then the bearing and punch are pressedinto place with an interference fit for accurately locating the bearingin the body portion. Then the punch is removed from the bearing.

The body portion 229 is provided with a pair of holes 245 and likewisethe disc 236 is provided with a pair of holes 246, these holes receivinga pair of downwardly projecting pins 247 which are riveted in place asindicated at 248. 'These downwardly extending pins 247 are provided withenlarged heads having a conical surface 249 and a bead 250. These pinsprovide means for removably securing a brush to the output gear and alsoprovide additional means for fastening the disc 236 to the body portion229 for clamping the tire in place.

The bracket 227 is illustrated in Figs. 1 and 2. It includes a pluralityof legs 252 terminating in attaching ears 253 having slots 254. Thebracket is secured to the base member by screws 255 and nuts 256, thescrews 255 passing through the slots 254 and suitable holes in the basemember. The lower surface of the bracket 227 has a plate 257 secured orWelded thereto as indicated at 258. The shaft 226 is provided with ashoulder resting against the plate 257 and is held in place on thebracket by peening over the upper end of the shaft as indicated at 260.A thrust Washer assembly is interposed between the disc 257 and theoutput gear bearing flange 243. This thrust bearing assembly includes ametal cup-shaped member 262 having a running engagement with the porousbearing flange 243 and a resilient washer 261 carried within thecup-shaped member 262. The resilient washer forms a resilient thrustbearing for the output gear. The lower end of the shaft 226 is providedwith an annular groove 263 for receiving a split washer 264 for holdingthe output gear in place on the shaft 226. The lower side of the outputgear is provided with a "cover 265 forenclosing the output gear bearing242 and the shaft 226 to prevent dirt and foreign material from goinginto the bearing.

The plate 257 overlies the disc 236 and is spaced a slight distancetherefrom. The plate 257 acts as a stop for the output gear to preventundue tilting of the output gear with respect to the machine. Thespacing between the plate 257 and the output gear disc 236 is such thatthe parts are not strained or stressed beyond their elastic limits whenand if tilting should occur.

The output gear bracket 227 is provided with an extension 267terminating in an ear 269 provided with a hole 270. An opening 268 isalso provided in the extension 267. The extension 267 and ear 269 forman outboard support for the cluster gear shaft 194. In this respect athrust Washer 271 of fiber or other suitable material is interposedbetween the cluster gear and the ear 269. I screw 272 is received in thelower end of the cluster gear shaft 194 for anchoring the same to ear269 of the bracket 227. The opening 268 in the extension 267 is foraccommodating the gears 193 and 225 so that these gears may mesh throughthat opening.

The gear teeth of the gears 193 and 225 are conventional in form andpreferably the gear teeth of the gear 225 are also cut or hubbed in theplastic tire after the tire has been secured in place on the bodyportion 229. This provides for accurate and ineXpensiVe formation of thegear.

In assembling the gearing enclosed within the inverted cup-shaped basemember 11, the gear 192 is first brought into proper meshing relationwith the motor pinion 153 and then the supporting bracket 195 issecurely fastened in place on the base member. Then the output gear 225is brought into proper meshing relation with the cluster gear 193 andthe supporting bracket 227 is then tightly secured to the base member.In this way correct meshing of the gearing is assured and themaintenance of close tolerance in the parts is not required.

The output gear detachably carries a rotatable brush. This brushincludes a brush backing 285 carrying a plurality of rows of brushbristles 286. The brush backing 285 of annular form is secured to asheet metal disc 2 57 by means of rivets 288. The disc 287 has anannular surface 289 for engaging an annular shoulder 29%) on the outputgear. The disc is connected with the output gear by means of pins 247 inthe manner fully described in the above mentioned co-pending applicationSerial #197,725.

From the above description, it is seen that the present invention hasprovided a novel gearing fully capable of accomplishing the objectsheretofore set forth. More specifically, it is seen the the presentinvention has provided a novel gearing which is of relatively simpleconstruction and may be inexpensively manufactured and assembled.Furthermore, it is seen that the gearing of the present inventioneliminates the necessity for gear boxes, gaskets, seals and the like. Inaddition, by reason of the novel construction of the gearing of thisinvention, increased operating life is obtained, and gear noises aresubstantially eliminated.

While for the purposes of illustration one form of this invention hasbeen disclosed, other forms thereof may become apparent to those skilledin the art upon reference to this disclosure and, therefore, thisinvention is to be limited only by the scope of the appended claims.

I claim as my invention:

1. A cluster gear comprising a metal body portion having a shank, acentral bore and an annular seating surface, a bearing in the centralbore for rotatably mounting the cluster gear, an absorbent washer forcontaining lubricant and contacting the bearing for supplying lubricantto the bearing, a gear carried by the shank of the body portion,interlocking means on the gear and the body portion for establishing adriving connection between the gear and the body portion, means forsecuring the gear in place on the shank of the body portion, a

tire having gear teeth seating on the annular seating surface of thebody portion, interlocking means on the tire and the body portion forestablishing a driving connection between the tire and the body portion,and means for securing the tire in place on the body portion.

2. A gear comprising, a gear body having a central bore provided with aninternal shoulder, a bearing memher having an external shoulder locatedin the central bore with the shoulders in engagement, an absorbentwasher for containing lubricant located in the central bore and engagingthe end of the bearing member for supplying lubricant to the bearingmember, and a metal washer secured to the gear body for retaining theabsorbent washer in place and for taking end thrust of the gear body.

3. A gear comprising, a gear body having a central bore, an annulargroove about the central bore and an annular seating surface, a porousbearing member located in the central bore and having a flange partiallyoverlying the annular groove and forming an end thrust member for thegear body, an absorbent washer for containing lubricant located in theannular groove and engaging the flange for supplying lubricant to theporous bearing member and its flange, a tire have gear teeth and seatingon the annular seating surface of the gear body, and an annular disccarried by the gear body for securing the tire in place on the gear bodyand also partially overlying the annular groove for maintaining theabsorbent washer in place therein.

4. A gear comprising, a body portion having a central bore and anannular seating surface, a bearing member in the central bore forrotatably mounting the gear, an absorbent washer for containinglubricant and contacting the bearing for supplying lubricant to thebearing, a tire seating on the annular seating surface and having gearteeth, interlocking means on the tire and body portion for establishinga driving connection between the tire and the body portion, and meansfor clamping the tire in place on the body portion.

5. A gear comprising, a gear body having a central bore, an annulargroove about the central bore and an annular seating surface, a porousbearing member having a bored sleeve portion and a flange at one end,said bearing member being accurately disposed within the central bore ofthe gear body, with the sleeve portion having an interference fit withthe central bore of the gear body and with the flange squared withrespect to the bore of the fitted sleeve portion and engaging the gearbody and partially overlying the annular groove, said bored sleeveportion of the bearing member forming a rotating bearing for the gearbody and said flange forming a thrust bearing for the gear body, anabsorbent washer containing lubricant located in the annular groove andengaging the flange for supplying lubricant to the porous bearing memberand its flange, a tire having gear teeth and seating on the annularseating surface of the gear body, and an annular disc carried by thegear body for securing the tire in place on the gear body and alsopartially overlying the annular groove for maintaining the absorbentwasher in place therein.

6. A cluster gear, comprising a body portion having a shank, a centralbore in said shank, and an annular seating surface, a gear carried bythe shank of said body portion, means extending from said body portionbetween the teeth of said gear for establishing a driving connectionbetween the gear and the body portion, and a tire having gear teethseating on the annular seating surface of the body portion.

References Cited in the file of this patent UNITED STATES PATENTS402,448 Hersh et al Apr. 30, 1889 (Other references on following page) 7UNITED STATES PATENTS Challincr Jan. 26, 1892 Alden et a1. June 26, 1917Plunkett June 24, 1924 Laddon et a1. Aug. 30, 1927 Frederick Nov. 26,1929 Adams July 28, 1931 8 Morton Oct. 30, 1934 Church NOV. 26, 1935Wcnnerstrom Dec. 31, 1935 Hoof Mar. 22, 1938 Colomb Oct. 22, 1940Etchells June 5, 1945 Clark Jan. 3, 1950

